1. Field of the Invention
The present invention relates to an operating power supply of a logic chip having a digital circuit installed in a multi-chip package semiconductor device.
2. Description of the Related Art
A digital circuit for logical processing of digital data can be voltage driven, generally at low power consumption. However, it is difficult to implement a power supply circuit within the digital circuit so as to provide sufficient current driving capability for driving the digital circuit.
For this reason, in the case of a logic chip on which digital circuits are integrated, the power required for the logic chip is often created and supplied by a power supply circuit using bipolar transistors fabricated on a separate chip.
For example, Japanese Patent Laid-Open Publication No. 2002-57270 discloses a semiconductor device having multiple chips of different types of power supply circuits where the respective power supply for each chip is received from a power supply circuit (not shown).